Day: May 21, 2017

Are you a Bitcoin miner or trader, but find yourself lacking the compulsive need to check exchange rates like the drug-fuelled daytraders of Wall Street? Fear not – you too can adorn your home or office with a Bitcoin Price Ticker! The post is in Italian but you can read a translated version here.

It’s a straightforward enough build – an Arduino compatible board with an onboard ESP8266 is hooked up with an HD44780-compatible LCD. It’s then a simple matter of scraping the Bitcoin price from the web and displaying it on the LCD. It’s a combination of all the maker staples, tied together with some off-the-shelf libraries – it’s quick, and it works.

[Ed: Oh boo! The images of the LCD were photoshopped. Please ignore the next paragraph.]

What makes the build extra nice is the use of custom characters on the LCD. The HD44780 is a character based display, and this project appears to use a screen with two lines of sixteen characters each. However, a custom character set has been implemented in the display which uses several “characters” on the screen to create a single number. It’s a great way to make the display more legible from a distance, as the numbers are much larger, and the Bitcoin logo has been faithfully recreated as well. It’s small touches like this that can really set a project apart. We’d love to see this expanded to display other financial market information and finished off in a nice case.

MIDI, or Musical Instrument Digital Interface, has been the standard for computer control of musical instruments since the 1980s. It is most often associated with electronic instruments such as synthesisers, drum machines, or samplers, but there is nothing to stop it being applied to almost any instrument when combined with the appropriate hardware.

The harmonica itself is mounted on a drawer slide coupled to a wheel taken from a pool sweeper and powered by a motor that can move the instrument from side to side with a potentiometer providing positional feedback to form a simple servo. The air supply comes from a set of three bellows driven via a crank from another motor, and is delivered by what looks like a piece of PVC pipe to the business end of the harmonica.

The result is definitely a playable MIDI harmonica, though it doesn’t quite catch the essence of the human-played instrument. Judge for yourselves, he’s posted a build video which we’ve placed below the break.

It’s time to talk about something of supreme importance to all Hackaday readers. The first trailer for the new Star Trek series is out. Some initial thoughts: the production values are through the roof, and some of this was filmed in Jordan (thank the king for that). The writers have thrown in some obvious references to classic Trek in this trailer (taking a spacesuit into a gigantic alien thing a la TMP). There are a few new species, even though this is set about 10 years before waaaait a second, those are the Klingons?

The Dayton Hamvention should have been this week, but it’s never going to happen again. The Hara Arena, the traditional venue for the biggest amateur radio meet on the continent (thankfully) closed this year. Last year it was looking old and tired. This year, Hamvention moved to Xenia, Ohio, and it looks like we’re still getting the best ham swap meet on the planet. Remember: if you drove out to Hamvention, the Air Force museum is well worth the visit. This year they have the fourth hangar open, full of space craft goodness.

Last week we saw an Open Source firmware for hoverboards, electric unicycles, and other explodey bits of self-balancing transportation. [Casainho], the brains behind this outfit, recently received an eBike controller from China. As you would expect, it’s based on the same hardware as these hoverboards and unicycles. That means there’s now Open Source firmware for eBikes.

This week saw the announcement of the Monoprice Mini Delta, the much-anticipated 3D printer that will sell for less than $200. For one reason or another, I was cruising eBay this week and came upon this. They say yesterday’s trash is tomorrow’s collectors’ item, you know…

The ESP32 is the next great wonderchip, and has been for a while now. The ESP32 also has a CAN peripheral stuffed in there somewhere, and that means WiFi and Bluetooth-enabled cars. [Thomas] has been working on getting a driver up and running. There’s a thread on the ESP32 forum, a Hackaday.io page, and a GitHub page.

What do you do when you have a nice old Vacuum Fluorescent Display and want to show some stats from your computer? You build a thing that looks like it’s taken from a cash register. This is a project from [Micah Scott], and it has everything: electronics 3D modeling, magnets, print smoothing, creating snap-fit parts, and beautiful old displays.

Here’s something that randomly showed up in our Tip Line. [Mark] recently found some unused HP 5082-7000 segment displays in a collection of electronic components (pics below). According to some relevant literature, these were the first LED display package available, ever. They were released in 1969, they’re BCD, and were obviously very expensive. [Mark] is wondering how many of these were actually produced, and we’re all interested in the actual value of these things. If anyone knows if these are just prototypes, or if they went into production (and what they were used for), leave a note in the comments.

There is a high probability that the device on which you are reading this comes somehow loosely under the broad definition of a PC. The familiar x86 architecture with peripheral standards has trounced all its competitors over the years, to the extent that it is only in the mobile and tablet space of personal computing that it has not become dominant.

The modern PC with its multi-core processor and 64-bit instruction set is a world away from its 16-bit ancestor from the early 1980s. Those early PCs were computers in the manner of the day, in which there were relatively few peripherals, and the microprocessor bus was exposed almost directly rather than through the abstractions and gatekeepers we’d expect to see today. The 8088 processor with an 8-bit external bus though is the primordial PC processor, and within reason you will find software written for DOS on those earliest IBM machines will often still run on your multiprocessor behemoth over a DOS-like layer on your present-day operating system. This 35-year-plus chain of mostly unbroken compatibility is both a remarkable feat of engineering and a millstone round the necks of modern PC hardware and OS developers.

Those early PCs have captured the attention of [esot.eric], who has come up with the interesting project of interfacing an AVR microcontroller to the 8088 system bus of one of those early PCs. Thus all those PC peripherals could be made to run under the control of something a little more up-to-date. When you consider that the 8088 ran at a modest 300KIPS and that the AVR is capable of running at a by comparison blisteringly fast 22MIPS, the idea was that it should be able to emulate an 8088 at the same speed as an original, if not faster. His progress makes for a long and fascinating read, so far he has accessed the PC’s 640KB of RAM reliably, talked to an ISA-bus parallel port, and made a CGA card produce colours and characters. Interestingly the AVR has the potential for speed enhancements not possible with an 8088, for example it can use its own internal UART with many fewer instructions than it would use to access the PC UART, and its internal Flash memory can contain the PC BIOS and read it a huge amount faster than a real BIOS ROM could be on real PC hardware.

USB power banks give your phone some extra juice on the go. You can find them in all shapes and sizes from various retailers, but why not build your own?

[Kim] has a walkthrough on how to do just that. This DIY USB Power Bank packs 18650 battery cells and a power management board into a 3D printed case. The four cells provide 16,000 mAh, which should give you a few charges. The end product looks pretty good, and comes in a bit cheaper than buying a power bank of similar capacity.

The power management hardware being used here appears to be a generic part used in many power bank designs. It performs the necessary voltage conversions and manages charge and discharge to avoid damaging the cells. A small display shows the state of the battery pack.

You might prefer to buy a power bank off the shelf, but this design could be perfect solution for adding batteries to other projects. With a few cells and this management board, you have a stable 5 V output with USB charging. The 2.1 A output should be enough to power most boards, including Raspberry Pis. While we’ve seen other DIY Raspberry Pi power banks in the past, this board gets the job done for $3.

VLF transmissions cover the 3-30 kHz range, and thus bandwidth is highly limited. VLF hardware is primarily used to communicate with submarines, often to remind them that, yes, everything is still fine and there’s no need to launch the nukes yet. It’s also used for navigation and broadcasting time signals.

It seems that this human transmission has created a barrier of sorts in the atmosphere that protects it against radiation from space. Interestingly, the outward edge of this “VLF Bubble” seems to correspond very closely with the innermost edge of the Van Allen belts caused by Earth’s magnetic field. What’s more, the inner limit of the Van Allan belts now appears to be much farther away from the Earth’s surface than it was in the 1960s, which suggests that man-made VLF transmissions could be responsible for pushing the boundary outwards.

Be careful what you say when you are shown a commercial product that you think you could make yourself, you might find yourself having to make good on your promise.

When he was shown a crowdfunded alarm clock coffee maker, [Fabien-Chouteau] said “just give me an espresso machine and I can do the same”. A Nespresso capsule coffee machine duly appeared on his bench, so it was time to make good on the promise.

The operation of a Nespresso machine is simple enough, there is a big lever on the front that opens the capsule slot and allows a spent capsule to drop into a hopper. Drop in a new capsule, pull the lever down to load it into the mechanism, then press one of the buttons to tell it to prime itself. After a minute you can them press either of the large cup or the small cup buttons, and your coffee will be delivered.

To automate this with an alarm clock there is no necessity to operate the lever, it’s safe to leave loading a capsule to the user. Therefore all the clock has to do is trigger the process by operating the buttons. A quick investigation with a multimeter on the button PCB found that the voltage present was 15 V, well above the logic level of the STM32F469 board slated for the clock. Thus a simple circuit was devised using a MOSFET to do the switching.

Finally, the clock software was created for the STM32F469. The chip’s 2D graphics acceleration hardware and the development board’s high quality display make for a very slick interface indeed.

You can see the resulting clock in the video below the break. It’s an alarm clock coffeemaker we’d be proud to have beside our beds, but there’s one slight worry. On a mains-powered device like the Nespresso the low voltage rails are not always mains-isolated, and it’s not clear whether or not this is the case. Maybe we’d have incorporated an opto-isolator, just in case.